A demodulator is a device or electronic circuit that extracts the original information-bearing signal (known as the modulating signal) from a modulated carrier wave. The process of extracting this original signal is termed as demodulation. In simpler terms, a demodulator reverses the process done by the modulator.
Key Components & Functions:
- Modulated Wave: The incoming wave that contains the information or data superimposed on a carrier wave.
- Recovered Signal: The output of the demodulator, which should be a close approximation of the original information signal before modulation.
Types of Demodulation:
- Amplitude Demodulation: Used to retrieve the message signal from an amplitude-modulated carrier wave.
- Frequency Demodulation: Used for recovering the original signal from a frequency-modulated wave.
- Phase Demodulation: Extracts the message signal from a phase-modulated carrier wave.
Applications:
- Radio Broadcasting: AM and FM radios use demodulators to convert transmitted signals back into audio signals.
- Television Broadcasting: Televisions employ demodulators to revert transmitted signals back into audio and video signals.
- Data Communication: Both wired and wireless communication systems use demodulators to extract digital data from modulated carrier waves.
In Summary:
A demodulator is the counterpart to a modulator. While the modulator’s role is to prepare a signal for transmission, the demodulator’s role is to retrieve the original information from the received signal. Together, modulators and demodulators enable the efficient and accurate transmission and reception of data and information over various communication channels.